POS0934 PREVALENCE AND TRENDS OF PULMONARY HYPERTENSION IN AUTOIMMUNE DISEASES
Authors: P. Khandwala, D. Desai, M. Sen
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Pulmonary hypertension (PHTN) is a known complication of connective tissue diseases such as Systemic lupus erythematosus (SLE), Scleroderma (Scl), and Mixed connective tissue disease (MCTD).<sup>[1]</sup> The underlying mechanism for development of PHTN is remodeling and vasoconstriction of pulmonary arteries and arterioles.<sup>[2]</sup> There have been cases of severe PHTN in SLE patients that have shown improvement with immunosuppressive therapy, hence accentuating the role of inflammation in pathogenesis.<sup>[3]</sup> The Prevalence of PHTN is not well studied, and there are no large cohort studies available. This study was undertaken to capture the trend in the prevalence of PHTN in the aforementioned diseases. <h3>Objectives</h3> To determine the prevalence of PHTN in SLE, Scl, and MCTD, analyze the trend over a 15-year period as well as identify racial predisposition, length of stay (LOS), and cost of hospitalization in these patients. <h3>Methods</h3> We used the Nationwide Inpatient Sample database (years 2003-2018) and extracted patients with PHTN using validated International Classification of Disease (ICD) codes. Data from 2015 was excluded from the study considering the transition of the coding system from version 9 to 10. We identified cases having the diagnosis of SLE, Scl, and MCTD. Prevalence, as well as demographics, cost of hospitalization, and length of stay (LOS), were analyzed and charted. Data were analyzed using statistical analysis system 9.4 software. <h3>Results</h3> Over the period of 15 years, we identified 2,155,750 cases of PHTN. As seen in the graph, patients with SLE had the highest prevalence of PHTN. The prevalence rate of SLE in PHTN cases in 2003 was 0.92% which significantly increased to 1.05% in 2018, with a peak of 1.15% seen in 2014 (p &lt;0.0001). Prevalence rate of Scl in PHTN decreased from 1.07% in 2003 to 0.80% in 2018 (p&lt; 0.0001). It was seen that the prevalence rate of MCTD in cases with PHTN significantly increased from 0.06% in 2003 to 0.23% in 2018, (p&lt;0.0001). It was observed that the average age of PHTN cases was significantly younger in SLE (55.60 vs 70.80 years, p &lt;0.0001), Scl (62.94 vs 70.72 years, p &lt; 0.0001), and MCTD (58.49 vs 70.66 years, p &lt;0.0001). On examining the racial distribution, African Americans, Hispanics, and Native Americans were more likely to have underlying SLE, Scl, and MCTD, respectively. PHTN was more prevalent in females in all 3 diseases. The average cost of hospitalization was significantly higher in PHTN cases with MCTD ($76,696.7 vs $65,643.3, p&lt;0.0001) and SLE ($69,106.5 vs $65,620.6, p&lt;0.0001), while it was not significantly lower in PHTN cases with Scl ($65,272.9 vs $65,659.9, p = 0.65). Average LOS was significantly longer in PHTN with MCTD (7.02 vs 6.64 days, p = 0.0119). Though not significant, average LOS was longer in PHTN with SLE (6.73 vs 6.64 days, p = 0.0812) and shorter in PHTN with Scl (6.62 vs 6.64 days, p = 0.7917). <h3>Conclusion</h3> Improved survival, seen secondary to increased awareness, better diagnostic testing, multidisciplinary team approach, and newer treatment modalities has led to an increase in the prevalence of patients living with PHTN. Interestingly, our study shows that the prevalence of PHTN in SLE and MCTD is increasing while decreasing for Scl. Racial predisposition becomes evident, which demands a higher index of suspicion for the early diagnosis of PHTN in the respective races. There is a higher socioeconomic burden for patients with PHTN and autoimmune disease, as reflected by the increased LOS and cost of hospitalization. <h3>References</h3> [1]Vonk MC, Vandecasteele E, van Dijk AP. Pulmonary hypertension in connective tissue diseases, new evidence and challenges. Eur J Clin Invest. 2021 Apr;51(4):e13453. doi: 10.1111/eci.13453. Epub 2020 Dec 5. PMID: 33216992; PMCID: PMC7988614. [2]Humbert M, Morrell N, Archer S, et al. Cellular and molecular pathobiology of pulmonary arterial hypertension. <i>J Am Coll Cardiol.</i> 2004 Jun, 43 (12_Supplement) S13–S24. [3]P. Dorfmüller, F. Perros, K. Balabanian, M. Humbert Inflammation in pulmonary arterial hypertension. European Respiratory Journal Aug 2003, 22 (2) 358-363; DOI: 10.1183/09031936.03.00038903 <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.